If you’re looking for research and studies on a particular topic, I highly suggest searching on frontiersin.org (at least to start). Frontiers is a collection of journals that seem to focus on really interesting cutting-edge stuff. I wanted to see what they had on chronic fatigue syndrome and damn, there’s some mind-blowing stuff there. There still seems to be no consensus but the research avenues opened here should hopefully lead to actual treatments in the future. Some interesting ideas I read included chronic low-level inflammation causing increased insulin resistance (and thus cells having to rely on lipid/protein metabolism for ATP production), low levels of T3 and higher levels of reverse T3 causing deficits in energy availability, overactivation of certain neural circuits causing dysfunction elsewhere in the brain, and increased production of ROS in mitochondria (which you can apparently treat by inhaling hydrogen gas??? Wild stuff).
Anyway, Frontiers. Give it a look if you have anything you need to look up in an academic journal.